Pages

Wednesday, January 30, 2013

Hot Air: Natural Gas and Climate Change

By Patrick RobbinsThe last year has witnessed a growing publicity campaign around the
notion that natural gas can act as a “transition fuel” – an energy
source with a smaller effect on the earth’s climate, an energy source we
can use as a substitute for dirty coal or oil while we begin the
transition to wind and solar. This idea has a particular appeal after
Hurricane Sandy: as climate change ravages our forests with droughts and
fires and batters our coastlines, we would be fools not to begin a
transition to low-impact fuels using the closest low-impact fuel at our
disposal, and that means using natural gas. Or so the argument goes.There
are plenty of holes in this argument, but let’s focus on the biggest
one: per unit, natural gas has not been demonstrated to have a lower
greenhouse effect on the Earth’s climate in comparison with coal and
oil. Indeed, if a recent study by NOAA scientists published in the
journal Nature is to be believed, the facts could be the exact opposite, at least in the short term.You
see, what we call “natural gas” is mostly methane. Methane is an
extremely potent greenhouse gas. While CO2 stays in the atmosphere
longer and is therefore more troubling over the long term, methane traps
a lot more energy during its time in the atmosphere. Compared
to Carbon Dioxide, Methane traps 72 times as much heat over a 20-year
period and 25 times as much heat over a 100-year period (according to
the IPCC). Unlike coal or fuel, the biggest area of concern for
natural gas is not emissions at the point of the fuel’s use—such the CO2
emitted when you drive a car—but the gases emitted at the point of
extraction. Even small amounts of methane leakage at the point of
extraction could negate the global warming benefits of methane as
compared to coal or oil.The study in Nature, published
in January 2013, found 4% methane leakages at a production site in
Colorado and 9% methane leakages at a production site in Utah, both well
above the EDF's 3.2% leakage
threshold after which methane starts actually being worse for the
climate than coal. It would be poor science indeed for us to extrapolate
general leakage rates from a mere two sites. However, both the
comparatively high numbers and the comparatively wide difference between
them are telling. In a recent article in Daily Finance,
one EDF scientist conjectured that the difference could be attributed
to the regulatory environment – Colorado has a more stringent regulatory
environment than Utah, and has been dealing with the natural gas issue
for a longer period of time.At the end of the day, this is an
argument for better science. We have to understand what our extraction
practices mean for our environment, so that we can craft germane
legislation, which would in turn encourage better reporting in a
virtuous cycle. But the cycle has to start somewhere. In the absence of
real science, propaganda takes its place in the public discourse, to the
detriment of both our discourse and our planet.